On helicopter decks where it, due to safety considerations for helicopter and surrounding structures, is necessary to secure the helicopter against wind damage, it is common practice to moor the rotor blades and the vessel body to the helicopter deck. The helicopter deck is normally provided with countersunk anchor points. With respect to governmental safety requirements imposing certain types of helicopter decks to be fluid tight, so that any fuel leakage is not lead through the helicopter deck to underlying structures, such countersunk anchor points are arranged in fluid tight housings. An anchoring element fixed in the housing, is accessible through an open top of the housing. Water and extraneous matter could therefore accumulate in these recessions, and under frost conditions, formation of ice in the recessions could complicate the access to the anchoring point.